Immobilization of heavy metal in contaminated mine technosols using biochar: A phytomanagement strategy

Soil contamination by metal(loid)s is one of the most important environmental problem. It leads to loss of environment biodiversity and soil functions and can have harmful effects on human health. Therefore, contaminated soils could be remediated, using phytomanagement. Indeed, plant growth will improve soil conditions while accumulating metal(loid)s and modifying their mobility. However, due to the poor fertility and high metal(loid)s levels of these soils, amendments, like biochar, has to be applied. Phytomanagement is a technique for rehabilitating these soils and reducing the spread of pollutants. To this end, it is advisable to stabilize the mobility of pollutants in the soil before planting plants. Biochar, produced by the pyrolysis of biomass under low oxygen conditions, has gathered attention in the last few years due to its capability to reduce metal(loid)s bioavailability and mobility in soils, as well as its beneficial effects on soil fertility. Indeed, biochar amendment to polluted soil induced usually an increase of pH, water holding capacity, and nutrient contents, associated with a decrease of metal(loid)s concentrations in soil pore water, through sorption on biochar. We tested different biochar concentrations from different wood feedstock in mesocosm and then on a field experimental plot presenting a significant arsenic (500 to 1000 mg/kg) and lead (15000 to 20000 mg/kg) pollution. Biochar from hardwood feedstock and more particularly the one obtained from bark and presenting the finest grain size (Lebrun et al. 2018) has shown good efficiency by reducing the availability of lead in soil pore water by more than 90% and keeping arsenic levels in the soil pore water below critical environmental concentrations. For the all plant species tested (Phaseolus, Populus, Salix, Ailanthus altissima, Alnus, Agrostis, and Trifolium) in biochar amended soils we show that biochar has allowed the establishment of a dense vegetation whereas until then the soils were bare and unsuitable for any plant development (Lebrun et al 2019, Nandillon et al 2019). Please click Additional Files below to see the full abstract

Increasing frailty is associated with higher prevalence and reduced recognition of delirium in older hospitalised inpatients: results of a multi-centre study

Purpose: Delirium is a neuropsychiatric disorder delineated by an acute change in cognition, attention, and consciousness. It is common, particularly in older adults, but poorly recognised. Frailty is the accumulation of deficits conferring an increased risk of adverse outcomes. We set out to determine how severity of frailty, as measured using the CFS, affected delirium rates, and recognition in hospitalised older people in the United Kingdom. Methods: Adults over 65 years were included in an observational multi-centre audit across UK hospitals, two prospective rounds, and one retrospective note review. Clinical Frailty Scale (CFS), delirium status, and 30-day outcomes were recorded. Results: The overall prevalence of delirium was 16.3% (483). Patients with delirium were more frail than patients without delirium (median CFS 6 vs 4). The risk of delirium was greater with increasing frailty [OR 2.9 (1.8–4.6) in CFS 4 vs 1–3; OR 12.4 (6.2–24.5) in CFS 8 vs 1–3]. Higher CFS was associated with reduced recognition of delirium (OR of 0.7 (0.3–1.9) in CFS 4 compared to 0.2 (0.1–0.7) in CFS 8). These risks were both independent of age and dementia. Conclusion: We have demonstrated an incremental increase in risk of delirium with increasing frailty. This has important clinical implications, suggesting that frailty may provide a more nuanced measure of vulnerability to delirium and poor outcomes. However, the most frail patients are least likely to have their delirium diagnosed and there is a significant lack of research into the underlying pathophysiology of both of these common geriatric syndromes

Naive Pluripotent and Trophoblastic Stem Cell Lines as a Model for Detecting Missing Proteins in the Context of the Chromosome-Centric Human Proteome Project

International audienceThe Chromosome-centric Human Proteome Project (C-HPP) aims at identifying the proteins as gene products encoded by the human genome, characterizing their isoforms and functions. The existence of products has now been confirmed for 93.2% of the genes at the protein level. The remaining mostly correspond to proteins of low abundance or difficult to access. Over the past years, we have significantly contributed to the identification of missing proteins in the human spermatozoa. We pursue our search in the reproductive sphere with a focus on early human embryonic development. Pluripotent cells, developing into the fetus, and trophoblast cells, giving rise to the placenta, emerge during the first weeks. This emergence is a focus of scientists working in the field of reproduction, placentation and regenerative medicine. Most knowledge has been harnessed by transcriptomic analysis. Interestingly, some genes are uniquely expressed in those cells, giving the opportunity to uncover new proteins that might play a crucial role in setting up the molecular events underlying early embryonic development. Here, we analyzed naive pluripotent and trophoblastic stem cells and discovered 4 new missing proteins, thus contributing to the C-HPP. The mass spectrometry proteomics data was deposited on ProteomeXchange under the data set identifier PXD035768

Unraveling hallmark suitability for staging pre- and post-implantation stem cell models

International audienceThe advent of novel 2D and 3D models for human development, including trophoblast stem cells and blastoids, has expanded opportunities for investigating early developmental events, gradually illuminating the enigmatic realm of human development. While these innovations have ushered in new prospects, it has become essential to establish well-defined benchmarks for the cell sources of these models. We aimed to propose a comprehensive characterization of pluripotent and trophoblastic stem cell models by employing a combination of transcriptomic, proteomic, epigenetic, and metabolic approaches. Our findings reveal that extended pluripotent stem cells share many characteristics with primed pluripotent stem cells, with the exception of metabolic activity. Furthermore, our research demonstrates that DNA hypomethylation and high metabolic activity define trophoblast stem cells. These results underscore the necessity of considering multiple hallmarks of pluripotency rather than relying on a single criterion. Multiplying hallmarks alleviate stage-matching bias

Induction of human trophoblast stem cells from somatic cells and pluripotent stem cells

International audienceHuman trophoblast stem cells (hTSCs) derived from blastocysts and first-trimester cytotrophoblasts offer an unprecedented opportunity to study the placenta. However, access to human embryos and first-trimester placentas is limited, thus preventing the establishment of hTSCs from diverse genetic backgrounds associated with placental disorders. Here, we show that hTSCs can be generated from numerous genetic backgrounds using post-natal cells via two alternative methods: (1) somatic cell reprogramming of adult fibroblasts with OCT4, SOX2, KLF4, MYC (OSKM) and (2) cell fate conversion of naive and extended pluripotent stem cells. The resulting induced/converted hTSCs recapitulated hallmarks of hTSCs including long-term self-renewal, expression of specific transcription factors, transcriptomic signature, and the potential to differentiate into syncytiotrophoblast and extravillous trophoblast cells. We also clarified the developmental stage of hTSCs and show that these cells resemble day 8 cytotrophoblasts. Altogether, hTSC lines of diverse genetic origins open the possibility to model both placental development and diseases in a dish

Polymer gradient surfaces for biomedical applications

Biological systems interact with artificial polymeric materials in a complex, multistage, and iterative process of sensing and response. The biological response at the cellular level to polymeric substrates has been studied at great length. However, this is often done on individual samples with a homogeneous feature. This results in experiments which are limited only to samples that the investigator can imagine — leaving potentially interesting samples or sample combinations hidden from use. Subtle variations in surface properties can have a drastic impact on cell response, and therefore a considered and careful approach must be employed in surface design and fabrication. Following the example set by combinatorial chemistry and high-throughput screening (HTS) applied to drug discovery by the pharmaceutical industry in the 1990s, researchers are increasingly turning to similar methodologies in biomaterial design. This involves creating high content samples for exploring the full sample space, usually taking the form of a highly multiplexed array platform, or a continuous variation of a single material property as a gradient. Creating such dense sample formats presents a series of unique challenges in both their fabrication and implementation. In the case of surface modification for biomedical applications, platforms must be created which offer broad variations in surface properties, and they must also be designed in such a way as to allow meaningful interpretation of often complex responses